Furnace



lMarch 16, 1937. F E, WADHAMS 2,073,769

FURNACE Filed May'4, 1935 5 Sheets-Sheet l rif, 1

'BY @A @ww ATTORNEY. v

March 16, 1937. F. B. wADHAMs FURNACE Filed May 4, 1933 5 Sheets-Sheet 2 [NVEN TOR.

IZG/

JM( BY A ORNEY.

March 16, 1937. F. B. WADHAMs 2,073,769

FURNACE Filed May 4, 1953 Sheets-Sheet 4 ATTORNEY.

March 16,137. F. B. wmf-AMS www FURNACE Filed May 4, 193:5 5 sheets-sheet 5 A TTORNE Y.

Patented Mar. 16, 1937 aan@ FURNACE Fred B. Wadhams, Cleveland Heights, Ohio, as-

signor to Wadert Co., Inc., Cleveland, Ohio, a

corporation of Ohio Application May 4, 1933, Serial No. 669,314

Claims.

This inventionrelates to furnaces, more particularly to an improved means for effecting combustion of generated gases and carbon, whereby maximum heat is produced from a given amount of fuel, resulting monoxide gases are reduced or eliminated and substantially all smoke is consuined, actual test with high volatile fuel showv complete combustion with resulting smoke reduced to a minimum.

Another object of the invention is to provide an improved burner for the gases of combustion and having means for supplying air to the gases of combustion while flowing through the burner, the walls of the burner and air supply serving to cause a turbulence of the gases of combustion while flowing through the burner.

Another object of the invention is to provide an improved burner comprising a plurality of spaced ports and an air supply for each of the ports and adapted to be associated with the combustion chamber or fire box of a furnace and incorporated with the walls thereof in such manner that the gases of combustion are caused to flow through the ports in passing to the combustion space, the spaced ports serving to break up the body of the-flowing gases, whereby the air is supplied into the interior of the gases to effeet a substantially uniform mixing therewith.

Another object of the invention is to provide an improved burner adapted to be associated with the combustion chamber of a furnace and comprising one or more ports for the gases of combustion having openings in their walls for supplying air into the body of the gases while flowing through the ports.

other object of the invention is to provide anx improved burner' adapted to be associated with the combustion chamber of a furnace and having inner walls vforrning a port through which gases of combustion flow and having openings for supplying air thereto and outer walls incorporated with the furnace structure and related to the inner walls to form spaces for the circulation of air whereby the supplied air is highlyheated before flowing through the openings` into the port.

Another object of the invention is to provide for a furnace an improved burner the construction of which adap-ts it to furnaces of different sizes and capacities, and permits of ready assembly, disassembly and replacements.

Other objects of the invention will be apparent Y to those skilled in the art to which the invention relates from the following description taken inv connection with the accompanying drawings, wherein Fig. 1 is a view of a furnace (with parts thereof broken away) having incorporated in it a burner embodying the invention, the burner being in section on the line I--l of Fig. 2.

Fig. 2 is a section on the line 2-2 of Fig. 1.

Fig. 3 is a section (enlarged) on the line 3 3 of Fig. 2.

Fig. 4 is a perspective rear view ofthe burner and associated walls of the furnace, with elements or parts of the burner and portions of the furnace walls omitted to facilitate illustration of the construction.

Fig. 5 is a View of elements or parts of the burner assembly, in perspective, in separated relation.

Fig. 6 is a view similar to Fig. 4, but with the refractory walls removed to show the assembly of the supporting members for the burner.

Figs. 7 and 8 are perspective views of details;

Figs. 9, 10 and 11 are detail views ofrrnodied forms of construction.

Fig. 12 is a section on the line l2-l2 of Fig. 11.

The invention herein disclosed is applicable to various types of furnaces or boilers, the eX- ample herein shown being of the low pressure boiler type. The combustion chamber for the furnace may be adapted for the 'combustion of fluid or solid fuel, but I have shown in the drawings a. furnace construction for burning solid fuel. In this form of construction, l indicates a plurality of sections constructed, when related in the usual manner, to form a combustion chamber abovea plurality of movable grate bars 2, and having front and rear walls la, Ib, respectively. 3 indicates the ash pit. The'front wall la is provided with a fire door 4 and the rear end wall Ib is formed with an opening connected to a combustion space from which leads a flue 5. The parts above described may be of any desired construction.

i indicates asian entirety a burner structure mounted in the furnace in such relation to the combustion chamber that the gases of combustion are caused to flow therethrough and air may be brought into intimate contact and mixed ,with the gases. whereby maximum combustion "conditions may be attained for any given amount of fuel. As later set forth, the burner or burner structure is so constructed that air is supplied simultaneously and continuously through the side, top and bottom walls that constitute air passages or ports within the burner, and discharged, in highly heated condition, into the body of the gases of combustion, as they flow through the burner so that intimate mixture with or injection of the air into the body of the gases takes place throughout its entire volume, whereby substantially complete combustion is effected while the gases are in an active or maximum heated condition. In such arrangement, the greater portion of the smoke produced is consumed, so that practically no smoke passes out of the flue and monoxide gases are changed to carbon dioxide gases.

The burner comprises one or more units (three being shown in the drawings) dependent upon the width of the furnace. In the preferred form of construction two or more units are provided, whereby the gases are caused to flow through separate ports. The air is supplied into and mixed with the gases flowing through each port, the effect of which is to inject air into the flowing gas body to cause a turbulent action thereof. 'Ihese units are (a) incorporated with adjacent walls of the furnace to cause all of the gases of combustion to ow through them and (b) preferably in connected relation to the ash pit or other area heated by the fire bed so that the supplied air is preheated to a relatively high temperature before entering the circulation spa-ces of the burner.

In the illustrated arrangement, the burner 6 is disposed at or adjacent the rear-most grate bar and preferably in a plane thereabove, so that the base portion of the burner forms a rear wall for the ire bed. Where the burner is mounted in a previously installed furnace, it is mounted on a pair'of rearward grate bars and connected thereto by a pair of cross members, as shown at 6' engaging the basal members and bolts 6:1: connecting the cross members together (one cross member and bolt being shown in Fig. 3). In this arrangement the pair of grate bars are disconnected from the grate bar shaking devices and the rear portion of the combustion chamber is closed at the bottom, as shown at I'.

As shown in Fig. 2, the burner is in contiguous relation to refractory side and top walls 'I of the furnace, whereby all of the gases of combustion are guided into and through the ports of the burner.

Referring to the burner 6, 8 indicates as an entirety a plurality of related basal members forming air conduits or channels in connected relation to the air supply and supporting a plurality of supports or supporting members to be later referred to, and 9 indicates as an entirety a plurality of refractory members related to form, for the respective units, ports III through which the gases of combustion flow and into which heated air is supplied to effect a turbulence of the gases and mixing of the heated air therewith.

When the furnace is constructed to receive the burner, the basal members 8 may be mounted on a pair of spaced bars I I (one being shown in Figs. 1 and 2). Where these bars II or the grate bars (as the case may be) are at a low level relative to the normal level of the re bed, I provide spacing means comprising a plurality of member pairs of hollow metallic members I2 and end members I2. 'Ihe basal members 8, supporting members II and spacing members I2, I2', are formed of suitable material, preferably a metal alloy, adapted to resist relatively high temperatures. The members I2 are preferably U- shape in cross section and oppositely related to form an unobstructed space between them communicating with the ash pit 3 (see Figs. 1 and 2) and the space or spaces within the basal members 8. The side walls I2a of the members I2, I2', are preferably respectively in the planes of the front and rear walls of the basal members 3 (see Figs. 1 and 3). The opposite ends of each I2 may be provided with webs I3. When the webs I3 are provided, they are slotted at I4 to receive bolts I5, which secure the members together. The members I2' are similar in construction and similarly connected to the adjacent intermediate members I2, except that each is preferably provided with an outer wall I2b (see Fig. 2), to close the space within the spacing members. The upper wall of each member I2 is formed with slots which register with slots I6 (see Figs. 5 and 6) formed in the bottom walls of the basal members 8, to receive suitable bolts which detachably connect the members I2 and basal members rigidly together.

The upper walls of the members I2 and bottom walls of the basal members 8 are provided with interlocking elements which insure their alignment, facilitate assembly, prevent their relative movement and prevent the escape of air. By preference, these elements consist of ribs I2c on the upper walls of the Spacing members I2 and complementary grooves 8a formed in the bottoms ofl the members 8 (see Fig. 3).

The basal members 8 comprise intermediate pairs of blocks I 1, I8, and end pairs of blocks I9, 20. 'I'he blocks are separable to permit of ready assembly and disassembly, interchangeability of parts, the provision of spacers and the assembly of different sizes of blocks, whereby the burner may be adapted to furnaces of different capacities and combustion chambers of. different sizes.

Each front block I'I comprises a side wall 2I, a projection 22 extending laterally from the central portion of the wall 2|, constituting a base for the support and attachment of the standards 30, to be later described, such projection being detachably connected to the side wall of the rear block I8 of the pair, end walls 23, a bottom wall 24 and flanges or webs 25, these parts being of metal and preferably formed integrally. The end walls 23 are formed with slots 26 which align with slots formed in the end walls of adjacent blocks I I and receive bolts 21, whereby the blocks are rigidly secured together. The central portion of the projection 22 and the flanges 25 are formed with relatively large openings 28, 28', respectively, for the flow of air from the space within the basal members 8, as hereinafter set forth, and at or near its opposite ends the projection 22 is formed with openings 29 in which are removably mounted uprights or standards 3B, forming certain of the supporting members already referred to. The upper ends of the standards 3i] support a bridge member 3|, on which the adjacent ends of supporting top plates 32 rest, the plates 32 serving as a support for and incorporated with the upper refractory furnace wall "i, as shown in Figs. l, 2 and 3. The flanges 25 are cut-away so as to provide for the free flow of air, especially where the bottom wall of the ow port is provided withone or more air` ports, as later set forth.

Each rear block I8 comprisesa Vside wall 2|a, end walls 23av and a bottom wall 24a. The end walls `23a-of each block aredetachably connected to the end walls of adjoining blocks similarly to the means for connecting the end walls of the blocks I1. The blocks I1, I8, of each pair are detachably connected in the following manner: 33 indicates a pair of integral lugs depending from the free end of the projection 22 and arranged to project into sockets 34 provided on the inner face of the wall 2| a of the rear block I8;

, the lugs 33 lit the sockets in such manner that the two blocks are held in rigid but detachable relation. One end wallof each block I1, I8, is formedwith a vertical groove 23.121 and the other endl wall of the block is provided with a vertical rib 230; arranged to project into the groove 235e of the adjacent end wall ofthe adjoining block. These elements form an vinterlock between adjoining blocks and facilitate their assembly in aligned relation and also prevent the escape of air.

'Ihe pairs of. end blocks I9, 20, are similar in construction to the blocks I1, I8, respectively, except that they are provided with end walls I9', 20', the end wall I9 for the block I9 being in the plane of and formed integrally With the outer side of the projection 22 and the end wall 20 for the block 20 being in the same plane. The end wall 20' extends below the adjacent portion of the projection and abuts the end wall I9 whereby each end wall may be provided with webs and connected together similarly to the connections provided between the blocks |1-I1 and |8-|8.

The upper ends of the standards 30 are provided with caps 35, and the bridge member 3| is provided with sockets 36 fitting vover the caps; also, the caps are formed at opposite sides of the webs of the standards with recesses 31 into which depending lugs 38 are adapted to 4fit to maintain the bridge member in fixed relation to the standards (see Fig. The bridge member comprises a cross bar 39 connecting the sockets 36 and an upstanding, central wall 40 on which the ends of the adjoining plates 32 rest, as already set forth. The plates 32 are provided with spaced arms 4| which engage the wall 40 and depending ends 42 which engage the remote side of. the wall. It will be noted that the arms 4| at one end of each plate are offset relative to the arms 4| at the other end thereof. This permits the ends of adjoining plates to lie in the same plane and rest on the adjacent wall 40. In this arrangement,

. the arms 4| on one plate t between the `arms 4| on the adjoining plate to close the spaces between them; also, the ends of the plates 32 are cutaway, as shown at 43 to receive up-standing lugs 44 provided on the wall 48 to prevent lateral shifting of the plates. The engagement of the cutaways with the lugs 44 and ends 42 with the wall 48, serve to connect the pairs of Standards together through the plates 32.

The refractory members 9 form the bottom walls, side walls, and top walls for the flow ports Il] and also serve to protect the standards 3|) and other metal parts from the intense heat due imperforate, as represented in Fig. 4, or formed with a plurality of openings 45a, as shown in Fig.

'7, to `admit air into the bottom of the body of gases of combustion. The front and rear edges of each block 45 are recessed, as shown at 45', so that these edges may lie over the top edges of the side walls 2|, 2| a. The side walls for each port comprise slabs 46 each supported on the adjacent projection 22 between a rib 41 provided thereon and shoulders 48 on the standards 30, the upper ends of the slabs resting against the sides of the sockets 36. In this arrangement, the slabs 46 of adjoining ports are spaced by the standards 36 to form a chamber for the air o-wing through the adjacent openings 28 formed in the projecting part 22. The slabs 45 are provided with a plurality of openings 49 to admit air into the body of gases of combustion at the sides thereof. The

openings 49 may be arranged in rows or staggered and when desired each wall may be provided with one or more baffles 58, adapted to agitate the gases while being mixed with air. Fig. 9 shows a side slab 46 provided with one baifle 50 centrally arranged and Fig. shows a slabl 46 provided with three baffles 56. Also, and by preference, the openings 49 are funnel shaped.

The top wall for each port Ill comprises a slab 5| suppo-rted at its opposite ends on the upper ends of the slabs 46 in spaced relation to the adjacent plate 32whereby a chamber is formed above the slab. The ends of the slabs 5| are cutaway along their central portions, as shown at 52, to permit air from the chamber between the slabs 46 to flow into the chamber above the slab 5 I. The slab 5| is formed with a plurality of openings 52a to supply air into the top portion of the body of gases of combustion flowing through the port Iii. The lateral openings 52a may be inclined inwardly as shown in Fig. 2. By preference, the opposite sides of each wall 48 of a bridge member 3| may be provided with' upwardly and outwardly inclined walls 53 which serve to deflect the air into the chambers above the slabs 5|. The spaces between the slabs 5| and plates 32 are closed along the opposite sides of the latter by refractory bars 1 disposed between the slabs 5| and refractory wall 1.

54 indicates refractory facing plates disposed outwardly of the standards 39 and extending between the end portions of adjoining slabs 5| and the Walls 2|, 2| a., of the blocks I1, I8, their side edges being flush with the inner faces of the slabs 46 and co-operating with the latter to form the air chambers between them. The opposite outer ends of each plate 54 are beveled at 55 to fit behind beveled ribs 56, 51, provided on the wall 2| or 2 Ia and slab 5|, respectively.

In assembling the refractory members 9 for each po-rt I 8, the top slab 5| is first positioned between the walls 46; next, the side slabs 46 are slid endwise into position (while the slab 5| is held in a raised position), the rib 51 along the front edge of the slab- 5| being slotted transversely at 58 (see Fig. 4) to admit the slabs 46; next, the facing plates 54 are aligned with the beveled ribs 56 and 51 and slid. endwise into position behind them, thereby locking the slabs y46 in position; the slab 5| is then lowered into engagement with the upperV edges of the slabs 46; next, the botto-m block 45 is dropped into position on the flanges 25; and nally the refractory bars 1' are positioned. It Vwill thus be seen that all of the walls of each port consist of refractory elements and that the metallic supporting members 36, 3| and32 are protected from the hot gases by these y elements and the facing blocks 54. The spaces between the slabs 5l, above the facing blocks 54, may be lled or closed with refractory inserts 54', which may be cemented in position.

It will be noted that the outer faces of the ribs 51 are inclined downwardly and inwardly, the purpose of which' is to deflect the gases of combustion downwardly and into the ports I whereby the turbulent action of the gases is increased.

Where the width of the furnace is greater than that equal to the distance or area occupied by the pairs of blocks II-I8 and lf3-20, one or more pairs of these blocks may be spaced by pairs of spacers 58a, one of such spacers being shown in Fig. 8. As shown, each spacer consists of a side wall 2 lx, end walls 23x and a bottom Wall 24x, the end and bottom walls being similar in construction to corresponding walls of the blocks |l-l8. The spacers may be of different lengths to accommodate the burner to different areas or sizes of furnaces. When the spacers 58a are required, blocks 45, slabs and plates 32 0f the desired size are used.

Figs. 11 and l2 illustrate a modified construction of the bottom wall or block for each port. In these views 45:1: indicates the block adapted to rest on the flanges and overlie the walls 2l and Zia. The central portion of the block is formed with an opening 45a in which is seated the hollow boss 45h of a deflecting member 45e which rests on the block, the boss being preferably formed integrally therewith. The deflecting member 45e is formed with an opening 45C registering with the opening through the boss to supply air into the port and has diverging sides disposed in the path of movement of the gases of combustion so as to deflect portions of the gases and permit the air to be injected into the interior of the gaseous body to effect an interrnixture of the air and gases. In this form of construction, the bottom of the block is recessed at 45d so that air flowing upwardly between the flanges 25 and through the openings 28 therein may enter the boss 45h.

It will be noted that in the herein disclosed construction, the several parts are separable and removable, but each is standardized or uniformly constructed to permit of interchangeability and assembly of different sized parts, whereby the burner may be adapted to furnaces the combustion chambers of which vary in width and height. For example, the width may be increased by the use of one or more pairs of spacers 58a; in such arrangement, blocks 45, slabs 5l and plates 32 of a size to compensate for the enlarged ports are used. Where it is necessary to increase the height of the ports, longer standards 30, plates 54 and slabs 46 are used.

By making the basal members of separable blocks, they may be formed of different materials.

It will also be noted that the channel between the spacing members l2 communicates with the ash pit 3, so that heated air hows into the basal member and through it and then through the openings 28, so that the heated air is simultaneously and continuously supplied to all of the ports or openings in the refractory Walls forming each port. Furthermore, it will be noted that the supplied air circulates in contact with the walls of the ports as well as the walls of the basal members 8 and therefore absorbs heat units therefrom.

The arrangement of the walls forming the ports for the gases of combustion and circulation of air is such that the air is highly heated by the walls of the ports, so that it flows through the air supply openings into the ports at a high velocity the effect of which is to cause a turbulent action of the gases and intermingling of the air therewith. When desired the surfaces of the walls (for example, the walls 46) forming the air curculation spaces may be provided with ribs to increase turbulence of the gases; also, the air openings in the walls 46 may be inclined rearwardly or the rearward Walls of these openings may be inclined rearwardly to direct the air in the direction of flow of the gases. Due to the mixing of the air with the hot gases an intense flame results in the flow ports, the effect of which is to heat the refractory walls to a high temperature, approximately 2000 F. or higher, which Walls in turn will heat the supplied air to a temperature sufficiently high to cause complete combustion. Accordingly, (a) the air is preheated to a high temperature for mixing with the gases and (b) the adjacent furnace walls are spaced by the air circulating spaces from the walls of the ports and therefore they are not subjected to undue high temperatures.

The re is started on the grate bars and maintained thereon in the usual manner, by the addition of fuel from time to time, an incandescent coke bed being maintained against the basal members 8.

After the fire, which has been started by burning the coal from the top, has become an incandescent bed of fuel containing no green coal, some of it is pushed back against the basal members or slightly into the openings of the burner. Then a fresh charge of green coal is thrown upon the incandescent bed of coals only in the front part of the re-box. The heat of the fuel bed will cause the volatile matter in the green coal to distill in the form of gases; and immediately one will notice heavy clouds of black and brown smoke arising from the freshly charged coal. As the smoke, which contains principally hydrocarbon, carbon monoxide, carbon dioxide and hydrogen gases along with carbon in the form of soot, passes through the coke bed, which has been piled up in front of the burner, it is heated to a temperature of ignition or higher. The temperature of the coke bed will be approximately 1400 F.; whereas carbon monoxide (CO) is formed at a temperature of about 950 F. and carbon dioxide near to 1250 F., which means that the carbon gases as they come into the burner ports will have a temperature higher than is required for their chemical union with oxygen. Any hydrocarbon gas such as methane (CH4) along with hydrogen (H2) and carbon monoxide (CO) will pass chemically unchanged into the burner ports where they will be completely burned; whereas any carbon dioxide (CO2) gas that is formed before it passes over the coke bed is reduced to carbon monoxide gas and is reoxidized to carbon dioxide by combustion within the burner.

The reason that these unburned gases are encountered is because only about one-half of the necessary air for combustion can be effectively supplied through the grate bars of the furnace, and so it is the object of the burner to supply the secondary air necessary for complete combustion at a temperature of approximately 750 F. The burner does this by pre-heating its own air. 'Ihe volume of air in the spaces between the ports and over the top of the latter is partially checked by its own pressure caused from expansion, which increases the velocity of the air into the ports, causing an excessive turbulence therein. Considering the state of affairs within the burner ports, all of thegases entering there have been pre-heated to their ignition temperature or even higher which means that their chemical affinity for each other is very great. They will readily mix in this condition, aided also by the turbulence which will exist because of the blasts of air issuing from the openings into the burner ports on both sides and from above. The temperature of the combustion products leaving the burner ports on their way toward the boiler flues has been found to be as high as 3200 F. by measurement.

To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the spiritand scope of the invention. The disclosures and the description herein are purely illustrative and not intended to be in any sense limiting.

What I claim is:

1. In a furnace having a combustion chamber and a flue, a burner structure through which the gases of combustion pass to the ilue, said structure including a hollow member formed with openings in its top wall and a refractory walled port mounted on said member substantially above the fuel in said combustion chamber, the side and top walls of said port being spaced from the walls of the furnace to define `air circulation channels connected with the openings in said hollow member to receive air therefrom, the side and top walls of said port being formed with openings to permit the air in said channels to flow into said port for admixture with the gases flowing through the latter to produce substantially completecombustion of the gases, and each of said side walls 40 being formed with la vertically disposed baffle between the openings therein.

2. In a furnace, the combination with a combustion chamber having a grateV for fuel, an ash pit below the grate and a flue, of a hollow mem- V ,45 ber comprising inner and outer vertical walls disposed transversely at the rear end of said grate and open along its bottom to receive air from said ash pit, the inner wall of said memberV forming the back wall for the fuel bed on said grate and arranged to be heated thereby, pairs of spaced metallic standards on said member, top plates mounted on said standards, sets of related blocks arranged to dei-lne flow ports between said pairs of standards, said top plates and said transverse member, each set of blocks comprising a refractory bottom wall, refractory side walls spaced from the side walls of adjoining ports by the adjacent 4standards to define air circulation spaces communicating with said hollow transverse member, and a refractory top wall spaced from said top plates to define air circulation spaces communicating with the first mentioned spaces, said side and top Walls being formed with openings to supply air into the adjacent port, and front and rear refractory walls between the side walls of adjoining ports on the outer sides of said standards.

3. In a furnace having a combustion chamber and a flue, a burner structure through which the 70 gases of combustion pass to said flue, said burner structure comprising a hollow member to which atmospheric air is freely admitted, open along its upper side andextending transversely between the side walls of said chamber Iat the rear 75 thereof to form the rear wall of the fuel bed in said chamber so as to be heated by the burning fuel therein, a refractory walled port mounted on said member to permit flowof the combustion products from the combustion chamber to the,

iiue, the sides and top walls of said port being spaced from the walls ofv said combustion chamber, and means surrounding the front and rear ends of said port for closing the spaces between said sides and top and the chamber walls to Idene air circulation chambers around the sides and top of said port which are arranged to receive heated air from said hollow member, 'at least one wall of said port being formed with an opening for supplying air from said chambers into the port for mixture with the gases to produce substantially complete combustion.

Y 4. In a furnace having a combustion chamber and a flue, a burner `structure through which the gases of combustion pass to said iue, saidburner structure being constructed to dene a refractory walled port having a bottom wall, side walls and a top wall and also to define air circulation chambers around the bottom wall, side walls and top wall of said port, said port being above the normal level of the fire bed in the chamber and each of said walls being formed with an opening for supplying air to the gases as they flow through said port for mixture therewith to produce substantially complete combustion, and a separable member seated in the opening in the bottom wall of said port and constructed to deflect the gases in advance of the opening through Said bottom wall.`

5. In a furnace having a combustion chamber and a flue, a burner structure through which the gases of combustion pass to said flue, said burner structure being constructed to denne a refractory walled port having a bottom wall, side walls and a top wall and also to define air circulation chambers around the bottom wall, side walls Iand top wall of said port, said port being above the normal level of the re bed in the chamber and each of said walls being formed with an opening for supplying air to the gases as they flow through said port for mixture therewith to produce substantially complete combustion, and 'a separable member seated in the opening through the bottom wall of said port arranged to deflect the gases in advance of such opening, said deilecting member comprising a device on said bottom wall and formed with an opening registering with the opening therein and having diverging side walls extending to either side of said opening.

6. A burner for a furnace comprising a hollow support arranged to be positioned at the rear and transversely of a combustion chamber and arranged to be heated by the burning `fuel in the chamber to heat the air in said support, pairs of standards on said support, an upper support mounted on said standards, refractory blocks mounted on said -hollow support below and in spaced relation to said upper support and between said pairs of standards and related to define ports through which the Agases of combustion flow, said ports being spaced, means at the front and rear ends of said ports for closing the spaces therebetween to define `air chambers between said ports in communication with said hollow support, means at the front and rear ends of said ports for closing the spaces between them and said upper support to define air chambers above said ports, the top blocks of said ports being cut away at their ends to permit air flow from the first mentioned air chambers to the last mentioned chambers, said blocks being formed with openings to supply air from said chambers into said ports, and means for supplying air to said hollow support.

7. In a furnace having a grate in its combustion chamber, an upper transverse wall at the rear of said chamber and a flue, of an air chamber extending transversely and at the rear of said grate substantially in the vertical planes of said upper 10 wall and connected with the ash pit below the grate to receive heated air therefrom and formed with openings in its upper wall, the front wall of said air chamber serving as the back wall for the bed of fuel on said grate, whereby the air in said chamber is heated to a higher temperature, a plurality of longitudinally extending spaced ports for the gases of combustion having walls of refractory material mounted on the upper wall of said air chamber and between it and said upper transverse wall, and means adjacent the front and rear ends of said ports co-operating with the side walls thereof for closing the spaces between said ports to complete air chambers arranged to receive air from said first mentioned air chamber through the openings in its upper wall, the

side walls of said ports being formed with openings to admit air from said last mentioned chambers into said ports, the walls of said ports serving to heat the air in the last mentioned chambers to a higher temperature to effect expansion thereof and ow into the ports at relatively high velocity.

8. In a furnace having a grate in its combustion chamber and a transverse wall above and at '35 the rear of said grate, of a burner structure comprising an air heating chamber extending transversely at the rear of said grate in the vertical planes of said transverse wall and formed with openings in its top wall and arranged to receive 40 heated air from the ash pit below said grate, a

series of spaced longitudinally extending refractory walls disposed vertically between the upper wall of said air heating chamber and said transverse wall, alternate spaces between said refractory walls having bottom and top walls co-operating therewith to form ports for the gases of combustion, and front and rear transverse end walls for closing the remaining spaces between said ports to form air heating chambers, said last mentioned heating chambers being connected with said first mentioned air chamber through the said openings in the top wall of the latter chamber and said longitudinally extending walls being formed with openings to admit the heated air from said last mentioned air chambers into said ports.

9. In a furnace having a grate, a combustion chamber above the grate, an ash pit below the grate and a ue, a burner structure disposed rearwardly of and transversely to said grate and incorporated with the walls of the furnace, whereby the gases of combustion are conducted through said structure, said structure comprising a hollow basal member forming the rear wall for '65 the fire bed on said grate in communication with said ash pit to receive heated air therefrom, sets of refractory members mounted on said basal member substantially above the re bed and relatedgto dene spaced ports through which the gases flow, the tops of said ports being spaced from the adjacent furnace wall and means adjacent the opposite ends of the ports for closing the spaces between said ports and between their tops and the furnace wall, said spaces being connected and the spaces between the ports having communication with the interior of said hollow member to receive heated air therefrom and said side and top members of the ports being formed with openings to supply heated air from said air spaces into the ports for mixture with the gases of combustion flowing through said ports to produce substantially complete combustion thereof.

10. In a burner structure for a furnace, the combination of a hollow basal member disposed transversely of the furnace and comprising detachably connected sections, spaced pairs of removable upright members mounted on said sections, supports removably carried by said members and incorporated with the adjacent wall of the furnace, sets of refractory elements comprising bottoms and sides removably carried by said sections, and tops removably carried by said upright members, the elements of each set being separably related and arranged to define a port through which the gases of combustion flow, the sides of each set of elements being spaced from the sides of adjacent sets to define air circulation spaces connected with the interior of said basal member, and the tops of said sets of elements being spaced from said supports to define air spaces above said tops, said tops being formed at their ends with recesses to permit air to iiow from said first mentioned spaces into said last mentioned spaces, one side and top of each set of elements being formed with openings for supplying air from said spaces to the adjacent port, and means for supplying air to said basal member.

11. In a furnace, the combination with a combustion chamber having a grate, an ash pit below the grate and a flue, of a multi-port burner rearward of the grate and incorporated with the walls of the furnace to direct the combustion gases through the ports of the burner, said burner comprising a metallic frame consisting of a hollow basal member extending transversely and arranged to be heated by the fuel burning in said chamber, pairs of standards on said member and spaced in longitudinal relation and top plates supported on the upper ends of said standards, and sets of refractory blocks defining ports for the combustion gases located substantially above the fuel level, mounted on said basal member between said pairs of standards, each port having a bottom wall, side walls and a top wall spaced from the adjacent top plate, and means adjacent the front and rear ends of said ports for closing the spaces between them to form air chambers connected to said basal member to receive heated air therefrom, at least one side wall of each port being formed with an opening to permit air to flow thereinto from the adjacent air chamber.

12. In a furnace, the combination with a combustion chamber and an ash pit therebelow, of pairs of front and rear blocks detachably connected and transversely arranged at the rear of said chamber and arranged to be heated by the fuel burning therein, said blocks being spaced to form between them a channel open at its top and communicating with said pit, sets of separable refractory blocks mounted on first mentioned blocks and spaced to define between the side walls of said sets of blocks air spaces communicating with said channel, each set of blocks being related to dene a port for the combustion gases substantially above the fuel in said chamber, and front and rear refractory blocks between the side walls of said sets of refractory blocks, the top walls of said ports being spaced from the furnace walls to define air circulation spaces communicating with said rst mentioned spaces.

13. A burner for a furnace arranged in the path of movement of the gases of combustion, having a transverse channel open at top and bottom to permit free circulation of air therethrough, and comprising a series of basal members formed of pairs of spaced front Yand rear blocks; pairs of spaced standards mounted upon the said basal members; sets of refractory blocks arranged to define ports for the gases of combustion, located above the said channel and between the pairs of standards; refractory blocks closing the spaces between the side walls of adjacent ports and protecting the standardsat the front and back, whereby are formed air circulation spaces between the ports communicating with the transverse channel,y and plates supported by the standards in spaced relation to the top walls of the ports to define thereabove air spaces which communicate with the air spaces between the ports, certain of the refractory blocks dening the gas ports being perforated to permit air to flow from the air spaces into the ports for `mixture with the gases of combustion flowing therethrough.

14. In a furnace having a combustion chamber for a bed of burning solid fuel, the hereix described burner for the products of combustion arising from said fuel bed comprising a transverse hollow base portion formed of material of high heat-conductivity, located to serve directly as a rear supporting wall for the bed of fuel, and also having openings to freely receive atmospheric air to be heated while in said hollow base portion; and a series of plates of material highly resistive to heat, arranged to form ports through which pass the products of combustion and gases arising from the bed of burning fuel, the said plates being spaced apart to form ilue spaces around the said ports, in free communication with the hollow base portion of the burner to receive the hot air therefrom and wherein it is further heated, the plates being perforated to permit the air to pass into the ports and mingle with the gases and products of combustion from the fuel bed.

l5. In a furnace having a combustion cham# ber for a bed of burning fuel and supported on a grate below which is an ash pit, the herein described burner comprising a transverse hollow base portion, made of material of relatively high heat-conductivity, located so as to serve directly as a rear support for the bed of fuel and being open at its bottom to freely admit atmospheric air from the ash pit and at a higher level to permit such airl to freely pass therefrom, and a ported portion through which the unburned gases and products of combustion from the bed of fuel pass, located above the said transverse portion of the burner, the said ports being surrounded by air passages receiving the heated air from the transverse portion of the burner and delivering it through perforations in the walls of the ports into the said gases and products of combustion passing through the ports.

FRED B. WADHAMS. 

